Photographic supersensitizing combinations comprising thienylcarbocyanine dyes



March 22, 1955 E. JONES 2,704,720 PHOTOGRAPHE suPERsENsITIzING COMBINATIONS COMPRISING THIENYLCARBOCYANINE DYEs Filed July 2o, 1954 B35 2`\,A 1111 www 1111 1111111 111111111 300 400 5.00 600 700 JEAN E. JONES INVENTOR.

ATTORNEYS United States Patent Office 2,704,720 Patented Mar. 22, 1955 PHOTOGRAPHIC SUPERSENSITIZING COMBINA- TIDNS CGMPRISING THIENYLCARBOCYANINE DYES Jean E. Jones, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New .iersey Application .uly 20, 1954, Serial No. 444,600

20 Claims. (Cl. 95-7) This invention relates to photographic emulsions containing cyanine (e. g., carbocyanine) dyes containing a meso thienyl group, and in supersensitizing combination, certain un-ionized dyes.

It is known in the art of making photographic emulsion that certain dyes of the cyanine class alter the sensitivity of photographic emulsions of the gelatino-silverhalide kind, when the dyes are incorporated in the emulsions. It is also known that the sensitization produced by a given dye varies somewhat with the type of emulsion in which the dye `is incorporated. Furthermore, the sensitization of a given emulsion by a given dye may be altered by varying the conditions in the emulsion. For example, the sensitization may be increased by increasing the silver ion concentration or decreasing the hydrogen ion concentration (i. e. increasing the alkalinity) or both. Thus, sensitization can be increased by bath-v ing plates, coated with a spectrally sensitized emulsion, in water or in aqueous solutions of ammonia. Such a process of altering the sensitivity of a sensitized emulsion by increasing the silver ion concentration and/or by decreasing the hydrogen ion concentration is commonly called hypersensitization Hypersensitized emulsions have generally poor keeping qualities.

I have now found an improved means of altering the sensitivity in emulsions containing cyanine dyes. Since the conditions in the emulsion, i. e. the hydrogen ion and/ or the silver ion concentration undergo little or no change in my method, I shall designate my method as a kind of supersensitization.

It is, therefore, an object of my invention to provide photographic emulsions containing cyanine dyes, and in supersensitizing combination therewith, certain un; ionized dyes. Another object is to provide a process for preparing these supersensitized emulsions. Other objects will become apparent from a consideration of the following description and examples.

The carbocyanine dyes containing a meso thienyl group useful in practicing my invention can advantageously be represented by the following general formula:

wherein R and R1 each represents an alkyl group, such as methyl, ethyl, n-propyl, carbethoxymethyl, etc., R2 represents a thienyl group (e. g., thienyl or substituted thienyl), m and n each represents a positive integer of from l to 2, X represents an acid radical, such as chloride, iodide, bromide, perchlorate, p-toluenesulfonate, benzenesulfonate, ethylsulfate, methylsulfate, etc., and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 t o 6 atoms in the heterocyclic ring, e. g., a heterocyclic nucleus of the thiazode series (e. g., thiazode, 4-methylthiazode, 4-phenylthiazole, S-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, etc.), a heterocyclic nucleus of the benzothiazole series (e. g., benzothiazole, 4-chlorobenzothiazole, S-chlorobenzothiazole, -chlorobenzothiazole, 7-chlorobenzothiazole, 4- methylbenzothiazole, S-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, -bromobenzothiazole, 4-phenylbenzothiazole, S-phenylbenzothiazole, 4 methoxybenzothiazole, 5 methoxybenzothiazole, 6- methoxybenzothiazole, -iodobenzothiazole, S-odobenzothiazole, 4-ethoxybenzothiazole, 5-ethoxybenzothiazole, 5,6 dimethylbenzothiazole, 5hydroxybenzothiazole, 6- hydroxybenzothiazole, etc.), a heterocyclic nucleus of the naphthothiazode series (e. g., u-naphthothiazole -naphthothiazole, 7-methoxy-a-naphthothiazole, S-methoxy-anaphthothiazole, 5-methoxy--naphthothiazole, S-ethoxya-naphthothiazole, etc.), a heterocyclic nucleus of the benzoselenazole series (e. g., benzoselenazole, 5-chlorobenzoselenazole, -methoxybenzoselenazole, S-methoxybenzoselenazole, etc.), a heterocyclic nucleus of the naphthoselenazole series (e. g. a-naphthoselenazole, naphthoselenazole, etc.), a heterocyclic nucleus of the benzoxazole series (e. g., benzoxazole, S-hydroxybenzoxazole, -hydroxyoenzoxazole, 5-chlorobenzoxaz0le, 5- methoxybenzoxazole, -methoxybenzoxazole, 5-phenylbenzoxazole, S-bromobenzoxazole, etc.), a heterocyclic nucleus of the naphthoxazole series (c g., a-naphthoxazole, -naphthoxazole, etc.), a heterocyclic nucleus of the 2- quinoline series (e. g. 2quinoline, 6-methyl-2-quinoline, 7methyl-2quinoline, S-methyl-Z-quinoline, 6-ch1oro-2- quinoline, S-chloro-Z-quinoline, 4-chloro-2-quino1ine, 5- ethoXy-2-quinoline, 6-ethoxy 2 quinoline, 7-ethoxy-2- quinoline, 6-hydroXy-2-quinoline, 7-hydroxy-2-quinoline, 6methoxy-2-quinoline, etc.), a heterocyclic nucleus of the 4-quinoline series (e. g., 4-quinoline, 6-methoxy-4-quinoline, 7-methyl-4-quinoline, 8-methyl-4-quinoline, etc.), etc.

The dyes represented by Formula I above wherein Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from those of the thiazole series, those of the benzothiazole series, those of the naphthothiazole series, those of the benzoselenazole series, those of the naphthoselenazole series, those of the benzoxazole series, or those of the naphthoxazole series (note that n represents l in all cases), have been found to be especially useful in practicing my invention.

The uri-ionized dyes useful in practicing my invention can advantageously be represented by the following general formula:

wherein R3 and R4 each represents an alkyl group, i. e. an alcohol radical, e. g., methyl, ethyl n-propyl, n-butyl, ,8-hydroxyethyl, carbethoxymethyl, benzyl (phenylmethyl), etc., Q represents the non-metallic atoms' necessary to complete an indandione nucleus or a heterocyclic nucleus containing from to 6 atoms in the heterocyclic ring, such as those of the pyrazolone series (e. g., 3- methyl-l-phenyl-S-pyrazolone, l-phenyl-S-pyrazolone, 1- (2-benzothiazolyl-3-methyl-S-pyrazolone, etc.), those of the isoxazolone series (e. g., 3-phenyl-5-(4H)isoxazo lone, 3-methyl5(4H)isoxazolone, etc.), those of the indandione series (e. g., l1-3-diltetohydrindene, etc.),

oxindoles, etc.), those of the 2,4,-triketohexahydropyrimidine series (e. g., barbituric acid or 2-thiobarbituric acid, as well as their l-alkyl (e. g., l-methyl, l-ethyl, 1- n-heptyl, etc.), or 1,3-dialkyl (e. g., 1,3-dimethyl, 1,3- diethyl, 1,3-di-n-propyl, 1,3-diisopropyl, 1,3-dicyc1ohexy1, 1,3-di(methoxyethyl), etc.), or 1,3-diary1 (e. g., 1,3- diphenyl, 1,3-di(p chlorophenyl), 1,3-di(pethoxycar bonylphenyl), etc.), or 1aryl (e. g., l-phenyl, l-p-chlorophenyl, 1-p-ethoxycarbonylphenyl, etc.) or 1-alkyl-3- aryl (e. g., 1-ethyl-3-phenyl, l-n-heptyl-3-pheny1, etc.) derivatives), those of the rhodanine series (i. e. 2-thio- 2,4-thiazolidinedione series), such as rhodanine, 3-alkylrhodanines (e. g. 3-ethylrhodanine, 3-allylrhodanine, etc.) or 3-arylrhodanines (e. g. 3-phenylrhodanine, etc.), etc., those of the imidazo [L2-a] pyridin-2(3H)one series, those of the 5,7-dioxo-6,7dihydro-5-thiazolo [3,2-al] pyrimidine series (e. g., 5,7-dioxo-3-phenyl-6,7dihydro 5-thiazole-[3,2a] pyrimidine, etc.), those of the 2-thio- 2,4-oxazolidinedione series (i. e. those of the 2-thio- 2,4(3H,5H)oxazoledione series) (e. g., 3-ethyl-2-thio- 2,4-oxazolidinedione, etc.), those of the thianaphthenone series (e. g., 2(3H)thianaphthenone, etc.), those of the 2-thio-2,S-thiazolidinedione series (i. e. the 2thio 2,5 (3H,4H)thiazoledione series) (e. g. 3-ethyl-2-thio- 2,5-thiazolidinedione, etc.), Z2 represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, e. g., a heterocyclic nucleus of the benzothiazole series (e. g. benzothiazole, 4 chlorobenzothiazole, 5 chlorobenzothiazole, -chlorobenzothiazole, 7-chlorobenzothiazole, 4-methylbenzothiazole, S-methylbenzothiazole, -methylbenzothiazole, 5-bromobenzothiazole, 6bromobenzothiazole, 4-phenylbenzothiazo1e, 5-phenylbenzothiazole, 4- methoxybenzothiazole, 5-methoxybenzothiazole, 6-methoxybenzothiazole, -iodobenzothazole, 5-iodobenzothiazole, 4-ethoxybenzothiazole, 5-ethoxybenzothiazole, 5,6- dimethoxybenzothiazole, 5-hydroxybenzothiazole, 6-hy droxybenzothiazole, 7hydroxybenzothiazole, etc.), a heterocyclic nucleus of the naphthothiazole series (e. g., a-naphthothiazole, ,S-naphthothiazole, 7-methoxy-a-naphthothiazole, 8-methoxy-a-naphthothiazole, 5methoxynaphthothiazole, 5-ethoxy-a-naphthothiazole, etc.), a heterocyclic nucleus of the benzoselenazole series (e. g., benzoselenazole, 5 chlorobenzoselenazole, 6-methoxybenzoselenazole, 5-methoxybenzoselenazole, etc.), a heterocyclic nucleus of the naphthoselenazole series (e. g., a-naphthoselenazole, -naphthoselenazole, etc.), a heterocyclic nucleus of the naphthoxazole series (e. g., a-naphthoxazole, -naphthoxazole, etc.), etc. and Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the naphthothiazole series (such as those listed above for Z2) or the naphthoselenazole series (such as those listed above for Z2).

Dyes of Formula H above which have been found to be particularly useful in practicing my invention include dyes selected from those represented by the following general formula:

wherein Ra, R4, Za and Q each have the values given above.

l ses Particularly useful are those dyes wherein Q represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the barbituric acid series and Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the naphthothiazole series or the naphthoselenazole series.

The dyes represented by Formula I above can be prepared as described in U. S. Patent 2,606,383, issued November l0, 1936, or in the copending applications of D. W. Heseltine, Serial Nos. 400,809 and 400,810, iiled December 28, 1953.

The dyes of Formula II (or III) are described in the copending applications Serial No. 282,696, led April 16, 1952, now abandoned and Serial No. 375,279, filed August 19, 1953, of F. L. White and Leslie G. S. Brooker.

According to my invention, I incorporate one or more of the cyanine dyes selected from those represented by Formula I above with one or more of the dyes selected from those represented by Formula II or III above in a photographic emulsion. My invention is particularly directed to the ordinarily employed gelatino-silver-halide emulsions. However, my supersensitizing combinations can be employed in silver halide emulsions in which the carrier is other than gelatin, e. g., a resinous substance or cellulosic material which has nodeteriorating effect on the light-sensitive materials.

The sensitizing dyes can be employed in various concentrations depending upon the effects desired. As is well known in the art, the sensitivity conferred upon an emulsion by a sensitizing dye does not increase proportionately to the concentration of the dye in the emulsion, but rather passes through a maximum as the concentration is increased. In practicing my invention, the individual sensitizing dyes are advantageously employed in a concentration somewhat less than their optimum concentration (i. e. the concentration at which the individual dyes give greatest sensitivity). If each of the dyes in the supersensitizing combination is employed in its optimum concentration, it is possible, in certain cases that the sensitization produced by the supersensitizing combination will have passed through a maximum.

The optimum concentration of an individual sensitizing dye can be determined in a manner well known to those skilled in the art by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing a different concentration of the sensitizmg dye. The optimum concentration of my supersensitizmg combinations, can, of course, be readily determined 1n the same manner, by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing different concentrations of the individual dyes 1n the combination. In determining the optimum concentration for the supersensitizing combination, it is advantageous to employ, at first, concentrations of the individual dyes less than their optimum concentrations. The concentrations of the individual dyes can then be increased until the optimum concentration of the supersensitizing combination is determined.

Ordinarily the optimum or near optimum concentration of the cyanine (i. e. carbocyanine) dyes selected from those represented by Formula I above, which I employ in practicing my invention, is of the order of from 0.05 to 0.3 g. per mol. of silver halide in the emulsion.

The un-ionized dyes selected from those represented by Formula II (or III) above are advantageously employed in concentrations on the order of from .01 to 0.3 g. per mol. of silver halide in the emulsion.

Generally speaking, the ratio of concentration of the dye of Formula II or III to the cyanine dye of Formula I can vary rather widely in my combinations, e. g., from 1:20 to 3 :1 by weight in many cases.

The methods of incorporating sensitizing dyes in emulsions are well known to those skilled in the art. In practicing my invention, the sensitizing dyes can be incorporated in the emulsions separately or together. convenient to add the dyes separately in the form of solutions in appropriate solvents. Methanol, ethanol, pyridine',

etc. (and especially pyridine) have proven satisfactory as solvents for the dyes of Formulas I, II, III which I employ. Acetone has also been found to be a suitable solvent in certain cases. In general, it is advantageous to employ pyridine, diluted with methanol or acetone, as

It isv the solvent for the supersensitizing combinations of my invention. For example, the dye can be dissolved in pyridine and the solution then diluted with methanol or acetone. The dyes are advantageously incorporated in the inished, washed emulsions and should be uniformly distributed throughout the emulsions. The following procedure is satisfactory: Stock solutions of the sensitizing dyes desired are prepared by dissolving the dyes in appropriate solvents as described above. Then, to the owable gelatino-silver-halide emulsion, the desired amounts of the stock solution of one of the dyes are slowly added, while stirring the emulsion. Stirring is continued until the dye is thoroughly incorporated in the emulsion. Then the desired amount of the stock solution of the second dye is slowly added to the emulsion, while stirring. Stirring is continued until the second dye is thoroughly incorporated. The supersensitized emulsion can then be coated out on a suitable support, such as glass, cellulose derivative lm, resin film, or paper, to a suitable thickness and allowed to dry. The details of such coating methods are well known to those skilled in the art.

The amounts of the individual sensitizing dyes actually incorporated in the emulsion will vary somewhat from dye to dye, according to the emulsion employed and according to the eect desired. The regulation and adoption of the most economical and useful proportions will be apparent to those skilled in the art upon making the ordinary observations and tests customarily employed in the art. Accordingly, the foregoing procedures and proportions are to be regarded only as illustrative. Clearly my invention is directed to any emulsion containing a combination of the aforesaid sensitizing dyes whereby a supersensitizing eiect is obtained.

The following examples will serve to illustrate further the manner of practicing my invention. To diierent portions of the same batch of photographic gelatine-silverbromiodide emulsion were added (l) a cyanine dye selected from those of Formula I and (2) a combination of the cyanine dye of Formula I and an un-ionized dye selected from those represented by Formula II (or III) above. In some instances, a third coating was prepared using the same emulsion formula and a single dye, one of the un-ionized dyes selected from those of Formula II (or III). In some instances, the table will show that this third coating gave only a low speed or one too low to measure in the region transmitted by the filter (designated asterisk in the table). Different emulsions were used in some of the examples, although the emulsions of each individual example were obtained from the same batch. However, the coatings of Examples 1 and 2 were obtained from the same batch, the coatings of Examples 3-8 were obtained from the same batch, the coatings of Examples 9 and l0 were obtained from the same batch, the coatings of Examples l1 and 12 were obtained from the same batch, and the coatings of Examples 13-20 were obtained from the same batch. Before coating, the emulsions were digested for a short time in a tank maintained at 52 C. The different portions of emulsions were then coated on supports and exposed in the usual manner in a spectrograph and a sensitometer (Type Ib) through a Wratten No. 25 lter, i. e., a lter which transmits substantially no light of wavelength shorter than 580 mu. (See Kodak Wratten Filters for Scientific and Technical Use, eighteenth edition, pages 31-2). The red speed, gamma and fog for each of the coatings were then determined after conventional development. The results are recorded in the following table.

Red Light Exposure EX, Dye (gJmole AgX) q.B0/E

peg Gamma Fog Filter (c) dye (a) (0.080) with dye (b) (0.030): 75.5 2.4 .06 9 {(d) 3,3diethyl9(2t hienyl)-4,5,4',5dibenzothiacarboeyanme p-toluenesull'onate (0080)..-. 14. 4 2. 6 06 dye (d) (0.080) with dye (b) (0.030) 90. 5 2. 4 .06

dye a 0.080) 9. 5 2. 6 .05 5 [(1ethy12(1H)naphthothiazolylidene)(1:methy12(1H)--naphthothiazolylidene) 13. 7 3. 5 06 isopropylidene]1,3di(dmethoxyethyl)barbiturie acid (0.080). dye (a) (0.080) with dye (g) (0 .030) 70. 5 2.5 .05 5[(1-ethyl-2(1H)-5-naphthothxazolylideuc) (lr uetl iyl-2(1H)-B-naphthoselenazolylidene) 12. 8 3. 3 05 isopropylidene]1,3di(methoxyethyl)harhituric acid (0.080). dye (a) (0.080) with dye (i) (0.030) 60.0 2.4 .05 dye (d) (0.080).. 9.7 2.7 .05 dye (d) (0.080) with dye (1) (0.00) 88. 5 2. 2 .06 5 [(1-ethyl-2(1H)--naphthothiazolylidene)(1-methy1-2(1H)naphthothiazolylldene) .07

isopropylidene]l-n-heptyl-3-phenylbnrbitmic acid (0.080). dye (d) (0.080) with dye (m) (0.030). 82. 5 2. 5 .05 3,3dimethyl9(Z-thienyl)thiacarboeyanme iodide (0.080)- 3. 5 0. 36 06 dye (b) (0.080). dye (o) (0.080) w1th dye (b) (0.030) 44. 4 2.8 .07 3,3'diethyl9(2-thieny1)thiacarbooyanine iodide (0.080) 3. 6 0.94 06 dye (r) (0.080) with dye (b) (0.030) 48. 5 3.1 07 dye (r) (0.080) 5.45 1.3 .07 1,a-thyl--[diuethyl-Z(1H)B-naphthothiazolylidene)isopropylidenelbarbiturie acid 27. 5 2. 0 06 dye (r) (0.080) with dye (u) (0.030) 51.0 2. 4 .08 dye (o) (0.080).- 3.80 0.94 .06 dye (o) (0.080) with dye (u) (0.030) 58. 5 2.3 08 dye (d) (0.080)..- 9.9 1.72 .05 4 [di( 1- a8t(1 1)yl2(1H)--naphthothiazolyhdene)isopropylidenel-B-phenyl-(4H)isoxazo 5.1 1.56 .05

one dye (d) (0.080) with dye (z) (0.030).... 38.0 1.84 .06 2-[di(Methyl-20H)fi-naphthothiazolylidene)1sopropy11dene]1,3mdandione (0.080) 04 dye (d) (0-030) With @Ye (b) (0.030) 48. 5 1.88 06 ,'dmthgfSQ-(Z-thienyl)4,5benzoth1ath1acarbocyamne p-toluenesulfonate (0.080) 3. 0 0.80 06 ye 0.0 dye (d') (0. 80) with dye (b) (0030).. 43.0 2.0 .06 1',3dimethy19-(2thienyl)4,5-benzothxa2'carboeyamne iodide (0.080) 04 dye (g') (0.080) with dye (b) (0.030). 24. 5 1. 5 .05 1ethy13methy1:9(2-thienyl)4,5be 04 dye (i') (0.080) with dye (b) (0.030) 5.1 1. 1 04 3,3'-dimethyl-9(2-thienyl)4,5,4,5'dibenzooxacarbooyan1ne lodlde (0.080) 4. 8 1. 4 06 dye (k) (0.080) with dye (b) (0.03 39.0 1.9 .06 3,3dimethyl9(2thienyl)4 5,4,5dibenzoselenacarbocyanine p-tolnenesulfonate (0.080) 5.8 1. 8 04 dye (m') (0.080) with dye (b (0.030) 33.0 2.0 .05 9-(2,-dichloro-B-thienyl)-3,3'din1ethylthiacarbocyanine iodide (0.080) 2. 6 0. 60 06 dye (o') (0.080) with dye (b) (0.030) 20.0 1. 6 .06 9-(2,5dichloro3thienyl)3,3'-diemthyl-4,5,4',5'd1benzothiacarhoeyanine iodide (0.080). .05 dye (q') (0.080) with dye (b) (01139)-.- 2.a 0.58 .05 5,5dichloro3,3dimethyl9(2-th1eny1)thlacarbocyanine p-toluenesulfonate (0.080) 05 dye (s) (0.080) with dye (b) (0.030) 21.0 1.9 .07

The coatings in Examples 9 and 10 of the above table contained 30 cc. of pyridine per mole of silver halide.

The accompanying drawing illustrates the supersensitizing eiect obtained with three of my new combinations of dyes in gelatino-silver-bromiodide emulsions. Each figure in the drawing is a diagrammatic reproduction of three spectrographs. In each ligure the sensitivity of the emulsion containing only the cyanine dye of Formula I is represented by the solid curve, the sensitivity of the same emulsion containing only the un-ionized dye of Formula II (or IH) is represented by the curve consisting of dotted lines, while the sensitivity of the same emulsion containing both the cyanine dye of Formula I and the un-ionized dye of Formula II (or III) is represented by the curve consisting of alternating long and short lines.

In Figure 1 curve A represents the sensitivity of an ordinary gelatino-silver-bromiodide emulsion sensitized with 3,3 dimethyl 9 (2 thienyl) 4,5,4,5 dibenzothiacarbocyanine p-toluene-sulfonate, curve B represents the sensitivity of the same emulsion sensitized with [(1 ethyl 2 1H) naphthothiazolylidene) (l methyl 2( 1H) naphthothiazolylidene)isopropylidene] 1,3 di( methoxyethyl)barbituric acid, and curve C represents the sensitivity of the same emulsion containing 3,3 dimethyl 9 (2 thienyl) 4,5,4,5 dibenzothiacarbocyanine p-toluenesulfonate and 5[(l ethyl 2(1H) naphthothiazolylidene) (l methyl- 2(1H) naphthothiazolylidene)isopropylidene] 1,3- di( methoxyethyDbarbituric acid. The sensitometric measurements for these emulsions are given in Example 3 of the above table. In Figure 2 curve D represents the sensitivity of an ordinary gelatino-silver-bromiodide emulsion sensitized with 3,3 dimethyl 9 (2 thieny1)thiacarbocyanine iodide, curve E represents the sensitivity of the same emulsion sensitized with 1,3diethyl5-[di(l-ethyl-2(1H)- naphthothiazolylidene)isopropylidene]barbituric acid, and curve F represents the sensitivity of the same emulsion containing both 3,3dimethyl9(2-thienyl)thiacar bocyanine iodide and l,3diethyl5[di( l-ethyl-2(1H) -naphthothiazolylidene) isopropylidene] barbituric acid. The sensitometric measurements for these emulsions are given in Example of the above table.

In Figure 3 curve G represents the sensitivity of an ordinary gelatine-silver-bromide emulsion sensitized with ous gold compounds (e. g., potassium chloroaurate, auric tn'chloride, etc.) (see U. S. Patents 2,540,085, 2,597,856 and 2,597,915), various palladium compounds, such as palladium chloride (U. S. 2,540,086), potassium chloropalladate (U. S. 2,598,079), etc., or mixtures of such sensitizers; antifoggants, such as ammonium chloroplatinate (U. S. 2,566,245), ammonium chloroplatinite (U. S. 2,566,263), benzotriazole, nitrobenzimidazole, 5nitro indazole, benzidine, mercaptans, etc. (see Mees-The Theory of the Photographic Process, Macmillan Pub., page 460), or mixtures thereof; hardeners, such as formaldehyde (U. S. 1,763,533), chrome alum (U. S. 1,763,533), glyoxal (U. S. 1,870,354), dibromacrolein (Br. 406,750), etc.; color couplers, such as those described in U. S. Patent 2,423,730, Spence and Carroll U. S. Patent 2,640,776, issued June 2, 1953, etc.; or mixtures of such addenda. Dispersing agents for color couplers, such as those set forth in U. S. Patents 2,322,027 and 2,304,940, can also be employed in the above-described emulsions.

In the above table it will be noted that in certain examples the amounts of dyes used in the supersensitizing combinations do not correspond to the amounts used with each dye alone. Actually, supersensitization occurs according to my invention when the combination of dyes gives more speed than either dye alone at any concentration. Thus, in some instances, the amount of dye, when used alone, is not identical with that used in the supersensitizing combination. This is due to the fact that optimum conditions have been used, insofar as possible, in each of the coatings. Use of larger amounts of dyes in the supersensitizing combinations is not necessary, and in some instances, is actually detrimental.

As noted above, the method of preparing dyes represented by Formula I above has been previously described in the art. It was found that dye (o) in the above table had a melting point of 217-8c C. decomp., dye (q) had a melting point of 203-4" C. decomp., and dye (s) had a melting point of 289-90 C. decomp.

What I claim as my invention and desire secured by Letters Patent of the United States is:

l. A photographic silver halide emulsion sensitized with a supersensitizing combination comprising at least one carbocyanine dye selected from those represented by the following general formula:

3,3 diethyl 9 (2 thienyl) 4,5,4,5' dibenzothiacarbocyanine p-toluenesulfonate, curve H represents the sensitivity of the same emulsion sensitized with 4-[di(1 ethyl 2(1H) naphthothiazolylidene)isopropylidene]-3phenyl5(4II)-isoxazolone, and curve I represents the sensitivity of the same emulsion containing both 3,3- diethyl 9 (2 thienyl) 4,5,4,5 dibenzothiacarbocyanine p toluenesulfonate and 4 [di(1 ethyl 2(1H) naphthothiazolylidene)isopropylidene] 3 phenyl- 5(4H)isoxazolone. The sensitometric measurements for thlse emulsions are given in Example 11 of the above ta e.

My invention is primarily directed to the ordinarily employed gelatno-silver-halide developing-out emulsions, e. g., gelatino-silver-chloride, chlorobromide, -chloroiodide, -chlorobromiodide, -bromide and bromiodide developing-out emulsions. While the results in the above tables were obtained using gelatino-silver-bromiodide emulsions, excellent results have also been obtained using gelatino silver chlorobromide emulsions. Emulsions which form the latent image mostly inside the silver halide grains, such as the emulsions set forth in U. S. Patent 2,456,956, dated December 21, 1948, can also be employed in practicing my invention.

The emulsions prepared in accordance with my invention can be coated in the usual manner on any suitable support, e. g., glass, cellulose nitrate lm, cellulose acetate film, polyvinyl-acetal resin film, paper or metal.

Photographic silver halide emulsions, such as those listed above, containing the supersensitizing combinations of my invention can also contain such addenda as chemical sensitizers, e. g., sulfur sensitizers (e. g., allyl thiocarbamide, thiourea, allylisothiocyanate, cystine, etc.), variwherein R and R1 each represents an alkyl group, R2 represents a thienyl group, X represents an acid radical, m and n each represents a positive integer of from 1 to 2, and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing 5 atoms in the heterocyclic ring when either m or n is l and 6 atoms in the heterocyclic ring when either m or n is 2, and at least one 11n-ionized dye selected from those represented by the following general formula:

wherein Ra and R4 each represents an alkyl group, Z2 1'epresents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoselenazole series, those of the naphthosclenazole series, and those of the naphthoxazole series, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the naphthothiazole series and those of the naphthoselenazole series and Q represents the non-metallic atoms necessary to complete a nucleus selected from the group consisting of those of the Iindandione series, those of the barbituric acid series, those of the 2-thiobarbituric acid series, and those of the isoxazolone series.

2. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizing combination comprising at 9 least one carbocyanine dye selected from those represented by the following general formula:

wherein R and R1 each represents an alkyl group of the formula CnHzn-.Li wherein n represents a positive integer of from 1 to 2, R2 represents a monocyclic thienyl group, X represents an acid radical, d represents a positive ineger of from 1 to 2, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the naphthoxazole series, and those of the naphthoselenazole series, and Z1 represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing atoms in the heterocyclic ring when d is 1 vand 6 atoms in the heterocyclic ring when d is 2, and at least one unionized dye selected from those represented by the following general formula:

wherein R3 and R4 each represents an alkyl group of the formula CmH2m+i wherein m represents a positive integer of from 1 to 2, Z2 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoselenazole series, those of the naphthoselenazole series, and those of the naphthoxazole series, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the naphthothiazole series and those of the naphthoselenazole series, and Q represents the non-metallic atoms necessary to complete a nucleus selected from the group consisting of those of the indandione series, those of the barbituric acid series, those of the 2-thiobarbituric acid series, and those of the isoxazolone series.

3. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizing combination comprising at least one carbocyanine dye selected from those represented by the following general formula:

wherein R and R1 each represents an alkyl group of the formula C1tH21t+1 wherein n represents a positive integer of from 1 to 2, R2 represents a monocyclic thienyl group, X represents an acid radical, d represents a positive integer of from 1 to 2, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the naphthoxazole series, and those of the naphthoselenazole series, and Z1 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the naphthoxazole series, those of the naphthoselenazole series, those of the 2-quinoline series, and those of the 4quino line series, and at least one un-ionized dye selected from those represented by the following general formula:

2,22" l/Z:\\ Rs--c=CH-tx3=cH- -n. /C\ Q ,Hje

wherein R3 and R4 each represents an alkyl group of the formula CmHzmJfi wherein m represents a positive integer of from 1 to 2, Zz represents the non-metallicatoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoselenazole series, those of the naphthoselenazole series, and those of the naphthoxazole series, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the naphthothiazoleseries and those of the naphthoselenazole series, and Q represents the non-metallic atoms necessary to complete a nucleus selected from the group consisting of those of the indandione series, those of the barbituric acid series, those of the 2thiobarbituric acid series, and those of the isoxazolone series.

4. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizing combinationl comprising at least one carbocyanine dye selected from those represented by the following general formula:

wherein R and R1 each represent an alkyl group of the formula CnH2n+1 wherein n represents a positive integer of from l to 2, X represents an acid radical, d represents a positive integer of from l to 2, Z represents the nonmetallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the naphthoxazole series, and those of the naphthoselenazole series, and Z1 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the naphthoxazole series, those-of the naphthoselenazole series, those of the 2-quinoline series, and those of the 4-quinoline series, and at least one un-ionized dye selected from those represented by the following general formula:

.A teger of from 1 to 2, Z2 represents lthe non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoselenazole series, those of the naphthoselenazole series, and those of the naphthoxazole series, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the naphthothiazole series and those of the napthoselenazole series, and Q represents the non-metallic atoms necessary to complete a nucleus selected from the group consisting of thos'e of the indandione series, those of the barbituric acid series, those of the 2-thiobarbituric acid series, and those of the isoxazolone series.

5. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizing combination comprising at least one carbocyanine dye selected from those represented by the following generalv formula:

wherein R and Ri each represents an alkyl group of the formula CnHzn+1 wherein n represents a positive integer of from l to 2, X represents an acid radical, d represents a positive integer of from 1 to 2, Z represents the nonmetallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the napthothiazole series, those of the naphthoxazole series, and those of the naph thoselenazole series, and Z1 represents the non-metallic atoms necessary to complete'a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those ofthe napthoxazole series, those of the naphthoselenazole 4-quinoline series, and at least one un-ionized dye selected from those represented by the following general formula:

wherein R3 and R4 each represents an alkyl group of the formula CmHzm-H wherein m represents a positive integer of from 1 to 2, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the naphthothiazole series and those of the naphthoselenazole series, and Q represents the non-metallic atoms necessary to complete a nucleus selected from the group consisting of those of the indandione series, those of the barbituric acid series, those of the 2-thiobarbituric acid series, and those of the isoxazoline series.

6. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizing combination comprising at least one carbocyanine dye selected from those represented bythe following general formula:

wherein R and R1 each represents an alkyl group of the formula CnHzn-l-i wherein n represents a positive integer of from l to 2, X represents an acid radical, d represents a positive integer of from l to 2, Z represents the non metallic atoms necessary to compute a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the naphthoxazole series, and those of the naphthoselenazole series, and Z1 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the naphthoxazole series, those of the naphthoselenazole series, those of the 2-quinoline series, and those of the 4- quinoline series, and at least one un-ionized dye selected from those represented by the following general formula:

wherein R3 and R4 each represent an alkyl group of the formula CmHzmq-i wherein m represents a positive integer of from l to 2, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the napthathiazole series and those of the naphthoselenazole series, and Q represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the barbituric acid series.

7. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizing combination of at least one carbocyanine dye selected from those represented by the following general formula:

,z` ,l R-N wherein R and R1 each represents an alkyl group of the formula CmHzm-x-i wherein m represents a positive integer of from 1 to 2, X represents an acid radical, and Z and Z1 each represents the non-metallic atoms necessary to wherein R3 and R4 each represents an alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 2, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the naphthothiazole series and those of the naphthoselenazole series, and Q represents the non-metallic atoms necessary to complete a nucleus selected from the group consisting of those of the indandione series, those of the barbituric acid series, those of the 2-thobarbituric acid series and those of the isoxazolone series.

8. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizng combination of at least one carbocyanine dye selected from those represented by the following general formula:

wherein R and R1 each represents an alkyl group of the formula CmHzm+1 wherein m represents a positive integer of from 1 to 2, X represents an acid radical, and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the naphthothiazole series, and at least one un-ionized dye selected from those represented by the following general formula:

9 I Ii: Q C O Ilh I I wherein R and R1 each represents an alkyl group of the formula CmHzm-y-i wherein m represents a positive integer of from 1 to 2, X represents an acid radical, and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one un-ionized dye selected from those represented by the following general formula:

wherein Rs and Rr each represents an alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 2, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the naphthothiazole series and those of the naphthoselenazole series, and Q represents the non-metallic atoms necessary to complete a nucleus selected from the group consisting of those of the indandione series, those of the barbituric acid series, those of the 2-thiobarbituric acid series and those of the isoxazolone series.

10. A photographic gelatine-silver-halide emulsion sensitized with a supersensitizing combination of at least one carbocyanine dye selected from those represented by wherein R and R1 each represents an alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 2, X represents an acid radical, and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one un-ionized dye selected from those represented by the following general formula:

wherein R3 and R4 each represents an alkyl group of the formula CmHzm-H wherein m represents a positive integer of from 1 to 2 and Q represents the non-metallic atoms necessary to complete a nucleus of the barbituric acid series.

ll. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizing combination of at least one carbocyanine dye selected from those represented IZA N-Rt e wherein R3 and R4 each represents an alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 2, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the naphthothiazole series and those of the naphthoselenazole series, and Q represents the non-metallic atoms necessary to complete a nucleus selected from the group consisting of those of the indandione series, those of the barbituric acid series, those of the 2-thiobarbituric acid series and those of the lsoxazolone series.

12. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizing combination of at least one carbocyanine dye selected from those represented by the following general formula:

wherein R and R1 each represents an alkyl group of the formula CmHzm-i-r wherein m represents a positive integer of from 1 to 2, X represents an acid radical, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the naphthothiazole series, and Z1 represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one un-ionized dye selected from those represented by the following general formula:

wherein R and R1 each represents an alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 2, X represents an acid radical, and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the naphthoxazole series, and at least one un-ionized dye selected from those represented by the following general formula:

wherein R3 and R4 each represents an alkyl group of the formula CmHzm-H wherein m represents a positive integer of from 1 to 2, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the naphthothiazole series and those of the naphthoselenazole series, and Q represents the nonmetallic atoms necessary to complete a nucleus selected from the group consisting of those ofthe indandione series, those of the barbituric acid series, those of the 2-thiobarbituric acid series and those of the isoxazolone series.

14. A photographic gelatine-silver-halide emulsion sensitized with a supersensitizing combination of at least 15 one carbocyaninedye selected from those represented by the following general formula:

wherein and R1 each represents an alkyl group .of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 2, X represents an acid radical, and Z and Z1 each represents the non-metallic atoms necessary to complete a heterocyclic nucleus of the naphthoxazole series, and at least one un-ionized dye selected from those represented by the following general formula:

C=CHC=CHC v\e N sitized with a supersensitizing combination of 3,3'di

bituric acid. n I v 16. A photographic gelatmo-sllver-hallde emulsion sensitized with a supersensitizing combination of 3,3'd1ethyl v 9-(2-thienyl)-4,5,4',5dibenzothiacarbocyanine p-toluene- 19. A photographic gelatino-silver-halide emulsion sensitized with a supersensitizing combination of 3,3dimeth yl-9-(2-thienyl)`f 4,5,4',5 dibenzooxacarbocyanne iodide and 5- [di( l-ethyl-2( 1H) --naphthothiazolylidene) isopropylidene] -l,3di(methoxyethyl)b arbturic acid.

20. A photographic gelatino-silver-bromiodide emulsion sensitized with a supersensitizing combination comprising at least one carbocyanine dye selected from those represented by the following lgeneral formula:

wherein R and R1 each represents an alkyl group of the formula CnHzM.; wherein n represents a positive integer of from 1 to 2, R2 repesentsja mnocyclc th`ienyl group, X represents an acid radical, d. represents a positive integer of from 1 to 2, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of' the benzothiazole series, those of the naphthethiazoleV series, those of the naphthoxazole series, and those of the naphthoselenazole series, and Z1 represents the non-metallic'atoms necessary to complete a heterocyclic nucleus containing 5 atoms in the heterocyclic ring when d is 1 and 6 atoms in the heterocyclic ring when d is 2, and' at least one un-ionized dye selected from those represented by the following general formula:

wherein R3 and R4 each represents an alkyl group of the formula CmHgm-ri wherein m represents a positive integer of from l to 2, Z2 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the naphthothiazole series, those of the benzoselenazole series,.those of the naphthoselenazole series, and those of the naphthoxazole series, Z3 represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected fromy the -group consisting of those of the naphthothiazoleseries and those of the naphthoselenazole series, and Q representsthe non-metallic atoms necessary to complete a nucleus selected from the group consisting of those of the indandione series, those of the barbituric acid series, those `.fnpthe 2-thiobarbituric. acid series, and those of the isoxazolone series.

No references cited. 

1. A PHOTOGRAPHIC SILVER HALIDE EMULSION SENSITIZED WITH A SUPERSENSITIZING COMBINATION COMPRISING AT LEAST ONE CARBOCYANINE DYE SELECTED FROM THOSE REPRESENTED BY THE FOLLOWING GENERAL FORMULA: 